FWIW, back when I had the original Motorola Droid and had it replaced a few times under the VZW extended warranty, there was only one time that the replacement had an immediate problem and they took care of that right away. I think I ended up getting replacements 4 times -- once for a non-working key on the keyboard, twice for the headphone jack shorting out (which was a well-reported problem for the original Droid for those who used headphones a lot) and once when the replacement wouldn't connect to wifi. My experience was that for the most part the refurbished replacements all lasted just as long as the original new droid did before developing the headphone short problem.
So I wouldn't worry too much about ending up with a refurb as long as you keep the total care insurance. And as I said earlier, I also wouldn't worry about the unlock icon.